The end of the First World War caused a brief economic crisis in Weimar Germany, permitting entrepreneurs to buy up varied businesses at rock-bottom prices. The most successful, Hugo Stinnes, established the most powerful private economic conglomerate in 1920s Europe - Stinnes Enterprises - which embraced sectors as diverse as manufacturing, mining, shipbuilding, hotels, newspapers, and an assortment of other economic enterprises.
Conglomerates were popular in the 1960s due to a combination of low interest rate(s) and a repeating bear/bull market, which allowed the conglomerates to buy companies in leveraged buyouts, sometimes at temporarily deflated values. Famous examples of the 1960s conglomerators include Ling-Temco-Vought, ITT Corporation, Litton Industries, Textron, Teledyne, and Gulf and Western Industries. As long as the target company had profits greater than the interest on the loans, the overall return on investment (ROI) of the conglomerate appeared to grow.
For many years this was enough to make the company's stock price rise, as companies were often valued largely on their ROI. The aggressive nature of the conglomerators themselves was enough to make many investors, who saw a "powerful" and seemingly unstoppable force in business, buy their stock. High stock prices allowed them to raise more loans, based on the value of their stock, and thereby buy even more companies. This led to a chain reaction, which allowed them to grow very rapidly.
However, all of this growth was somewhat illusory. As soon as interest rates started to rise in order to offset inflation, the profits of the conglomerates fell. Investors also noticed that the companies inside the conglomerate were growing no faster than they had before they were purchased, whereas the rationale for buying a company was often that "synergies" would lead to more efficiency. By the late 1960s they were frowned on by the market, and a major sell off of their shares ensued. In order to keep the companies going, many conglomerates were forced to shed the industries they had purchased recently, and by the mid-1970s most had been reduced to shells. The conglomerate fad was subsequently replaced by newer ideas like focusing on a company's core competency.
Cash flush during the 1980s, General Electric also moved into financing and financial services, which in 2005 accounted for about 45% of the company's net earnings. GE also owns a majority of NBC Universal, which owns a major American television network. In some ways GE is the opposite of the "typical" 1960s conglomerate: the company was not highly leveraged, and when interest rates went up they were able to turn this to their advantage as it was often less expensive to lease from GE than buy new equipment using loans. United Technologies has also proven to be an extremely successful example of a conglomerate.
Another example of a successful conglomerate is Berkshire Hathaway, which used its insurance surplus to invest in a variety of manufacturing and service businesses.
The best known British conglomerate was Hanson plc. It followed a rather different timescale than the U.S. examples mentioned above, as it was founded in 1964 and ceased to be a conglomerate when it split itself into four separate listed companies between 1995 and 1997.
In Japan, a different model of conglomerate, the keiretsu, envolved. Whereas the Western model of conglomerate consists of a single corporation with multiple subsidiaries controlled by that corporation, the companies in a keiretsu are linked by interlocking shareholdings and a central role of a bank. Mitsubishi is one of Japan's best known keiretsu, reaching from automobile manufacturing to the production of electronics such as televisions.
In South Korea, Chaebol is a type of conglomerate owned and operated by a family. Chaebol is also inheritable as most of current presidents of Chaebol succeeded their fathers or grandfathers. Some of the well-known Korean Chaebols are Samsung, LG and Hyundai Kia Automotive Group.